A process of separating aromatic compounds is to obtain para-xylene and benzene as main final products by processing a naphtha feedstock in a petrochemical plant. To obtain para-xylene, one of important products among aromatic compounds, a process of separating it from a xylene mixture has been commonly used. As examples of such process, there are processes using simulated moving bed adsorptive chromatography and crystallization caused by freezing point difference in each component, or a hybrid process which uses both processes together by connecting them serially, and the like.